Spam Filter ISP Forums : non delivery (NDR) not getting back to sender

Spam Filter ISP Forums : non delivery (NDR) not getting back to sender https://www.logsat.com/spamfilter/forums/ Sun, 08 Mar 2026 07:24:21 +0000 Tue, 14 Dec 2010 22:24:42 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 11.04 360 https://www.logsat.com/spamfilter/forums/RSS_post_feed.asp?TID=6902 <![CDATA[Spam Filter ISP Forums]]> https://www.logsat.com/spamfilter/forums/forum_images/web_wiz_forums.png https://www.logsat.com/spamfilter/forums/ <![CDATA[non delivery (NDR) not getting back to sender : njtech,By default SpamFilter...]]> https://www.logsat.com/spamfilter/forums/forum_posts.asp?TID=6902&PID=13933&title=non-delivery-ndr-not-getting-back-to-sender#13933 Author: LogSat
Subject: 6902
Posted: 14 December 2010 at 10:24pm

njtech,

By default SpamFilter will include the entire message in an NDR. If your Exchange server rejects an email from SpamFilter, then SpamFilter will generate an NDR for the sender, and will forward that NDR for delivery to your Exchange server. If the original rejection by Exchange was due to an excessive message size, the NDR will also be exceeding the max message size, as the NDR contains the original email within it.

To solve this issue, we actually recently posted a new SpamFilter build (4.2.4.840) that includes support for the following option in the SpamFilter.ini file:

// New to VersionNumber = '4.2.4.840';

{TODO -cNew Added support for a new parameter in the SpamFilter.ini file to control if the NDR will contain the entire original email or only its headers: IncludeOriginalMessageOnNDR=1}

If you thus set that value to "0" that should take care of the problem. You can manually add that parameter if it doesn't exist yet.

Edited by LogSat - 14 December 2010 at 10:25pm]]> Tue, 14 Dec 2010 22:24:42 +0000 https://www.logsat.com/spamfilter/forums/forum_posts.asp?TID=6902&PID=13933&title=non-delivery-ndr-not-getting-back-to-sender#13933 <![CDATA[non delivery (NDR) not getting back to sender : I have spamfilter isp setup to...]]> https://www.logsat.com/spamfilter/forums/forum_posts.asp?TID=6902&PID=13932&title=non-delivery-ndr-not-getting-back-to-sender#13932 Author: njtech
Subject: 6902
Posted: 13 December 2010 at 8:35pm

I have spamfilter isp setup to forward to a exchange 2010 server. If a recipient sends to a invalid exchange address the recipient will get a NDR (non delivery report) no problem works as desired.

However, if the email attachment size exceeds what is allowed on the

exchange server the ndr is never gets back to the recipient. At first

glance it appears its a exchange problem however if

I remove spamfilter the NDR works. any suggestions?

in the spam filter logs I see this:( I masked the actual email addresses and server name)

12/13/10 15:54:51:083 -- (24480) Error-email from sender@address.com to recipient -- was forwarded to myexchangeserver:25

12/13/10 15:54:51:083 -- (24480) There was an error sending the NDR to: sender@email The remote server said:validuser@gmail.com: 550 5.7.1 Unable to relay --

12/13/10 15:54:51:130 -- (24480) server error - myexchangeserver:25 said: 5.3.4 Message size exceeds fixed maximum message size --

]]> Mon, 13 Dec 2010 20:35:14 +0000 https://www.logsat.com/spamfilter/forums/forum_posts.asp?TID=6902&PID=13932&title=non-delivery-ndr-not-getting-back-to-sender#13932